COVID-19 Outcomes and Diabetes Mellitus: A Comprehensive Multicenter Prospective Cohort Study

The link between type 2 diabetes (T2D) and the severe outcomes of COVID-19 has raised concerns about the optimal management of patients with T2D. This study aimed to investigate the clinical characteristics and outcomes of T2D patients hospitalized with COVID-19 and explore the potential associations between chronic T2D treatments and adverse outcomes. This was a multicenter prospective cohort study of T2D patients hospitalized with COVID-19 in Greece during the third wave of the pandemic (February-June 2021). Among the 354 T2D patients included in this study, 63 (18.6%) died during hospitalization, and 16.4% required ICU admission. The use of DPP4 inhibitors for the chronic management of T2D was associated with an increased risk of in-hospital death (adjusted odds ratio (adj. OR) 2.639, 95% confidence interval (CI) 1.148-6.068, p = 0.022), ICU admission (adj. OR = 2.524, 95% CI: 1.217-5.232, p = 0.013), and progression to ARDS (adj. OR = 2.507, 95% CI: 1.278-4.916, p = 0.007). Furthermore, the use of DPP4 inhibitors was significantly associated with an increased risk of thromboembolic events (adjusted OR of 2.249, 95% CI: 1.073-4.713, p = 0.032) during hospitalization. These findings highlight the importance of considering the potential impact of chronic T2D treatment regiments on COVID-19 and the need for further studies to elucidate the underlying mechanisms.

Prone Position Ventilation in Severe ARDS due to COVID-19: Comparison between Prolonged and Intermittent Strategies

Ventilation in a prone position (PP) for 12 to 16 h per day improves survival in ARDS. However, the optimal duration of the intervention is unknown. We performed a prospective observational study to compare the efficacy and safety of a prolonged PP protocol with conventional prone ventilation in COVID-19-associated ARDS. Prone position was undertaken if P/F < 150 with FiO₂ > 0.6 and PEEP > 10 cm H₂O. Oxygenation parameters and respiratory mechanics were recorded before the first PP cycle, at the end of the PP cycle and 4 h after supination. We included 63 consecutive intubated patients with a mean age of 63.5 years. Of them, 37 (58.7%) underwent prolonged prone position (PPP group) and 26 (41.3%) standard prone position (SPP group). The median cycle duration for the SPP group was 20 h and for the PPP group 46 h (p < 0.001). No significant differences in oxygenation, respiratory mechanics, number of PP cycles and rate of complications were observed between groups. The 28-day survival was 78.4% in the PPP group versus 65.4% in the SPP group (p = 0.253). Extending the duration of PP was as safe and efficacious as conventional PP, but did not confer any survival benefit in a cohort of patients with severe ARDS due to COVID-19.

Heparin-induced thrombocytopenia thrombosis after cardiac surgery. A case report

We report a rare case of cerebral infarct resulting in brain death due to heparin-induced thrombocytopenia thrombosis (HITT), manifested in the immediate postoperative period following aortic valve replacement in a 46-year-old woman whose only prior exposure to heparin was during catheterization four months prior to surgery. The diagnosis of HITT was suspected after a significant decrease of the platelet count and it was confirmed by a heparin-induced platelet activation assay showing platelet aggregation in the presence of heparin.

Contribution of lung function to exercise capacity in patients with chronic heart failure

BACKGROUND

The importance of exercise capacity as an indicator of prognosis in patients with heart disease is well recognized. However, factors contributing to exercise limitation in such patients have not been fully characterized and in particular, the role of lung function in determining exercise capacity has not been extensively investigated.

OBJECTIVE

To examine the extent to which pulmonary function and respiratory muscle strength indices predict exercise performance in patients with moderate to severe heart failure.

METHODS

Fifty stable heart failure patients underwent a maximal symptom-limited cardiopulmonary exercise test on a treadmill to determine maximum oxygen consumption (VO2max), pulmonary function tests and maximum inspiratory (PImax) and expiratory (PEmax) pressure measurement.

RESULTS

In univariate analysis, VO2max correlated with forced vital capacity (r = 0.35, p = 0.01), forced expiratory volume in 1 s (r = 0.45, p = 0.001), FEV1/FVC ratio (r = 0.37, p = 0.009), maximal midexpiratory flow rate (FEF25-75, r = 0. 47, p < 0.001), and PImax (r = 0.46, p = 0.001), but not with total lung capacity, diffusion capacity or PEmax. In stepwise linear regression analysis, FEF25-75 and PImax were shown to be independently related to VO2max, with a combined r and r2 value of 0. 56 and 0.32, respectively.

CONCLUSIONS

Lung function indices overall accounted for only approximately 30% of the variance in maximum exercise capacity observed in heart failure patients. The mechanism(s) by which these variables could set exercise limitation in heart failure awaits further investigation.

Pulmonary function and respiratory muscle strength in chronic heart failure: comparison between ischaemic and idiopathic dilated cardiomyopathy

OBJECTIVE

To compare pulmonary function and respiratory muscle strength in patients with ischaemic and idiopathic dilated cardiomyopathy, well matched for indices of heart failure.

METHODS

The study involved 30 patients with ischaemic cardiomyopathy and 30 with idiopathic dilated cardiomyopathy. The groups were well matched for age, weight, and clinical severity of cardiac dysfunction as assessed by ejection fraction and the New York Heart Association functional class. There were more smokers in the ischaemic group (p < 0.05), but indices of pulmonary function were comparable.

RESULTS

Mean (SD) maximum static inspiratory pressure was lower in dilated cardiomyopathy than in ischaemic cardiomyopathy (73 (20) v 84 (22) cm H2O, p < 0.05), as was the maximum static expiratory pressure (90 (20) v 104 (21) cm H2O, p < 0.05).

CONCLUSIONS

For a given degree of cardiac dysfunction, the respiratory muscles are weaker in patients with idiopathic dilated cardiomyopathy than in those with ischaemic cardiomyopathy.

Effects of severity of long-standing congestive heart failure on pulmonary function

To investigate the effects of severity of long-standing congestive heart failure (CHF) on pulmonary function, we studied 53 (47 men) consecutive patients, all heart transplant candidates. Their mean (+/- SD) age and ejection fraction were 47 +/- 12 years and 23 +/- 7%, respectively. All patients underwent spirometry, lung volume, diffusion capacity (DLCO), maximum inspiratory (PImax) and expiratory pressure (PEmax) measurement. Maximum cardiopulmonary exercise test on a treadmill was also performed to determine maximum oxygen consumption (VO2max). On the basis of VO2max, the patients were then divided into those with a VO2max > 14 ml min-1 kg-1 (group 1, n = 30) and those with a VO2max < or = 14 ml min-1 kg-1 (group 2, n = 23). In comparison with group 1, group 2 patients had lower FEV1/FVC (70 +/- 8% vs 75 +/- 7%, P = 0.008), lower FEF25-75 (46 +/- 21 vs 70 +/- 26%pred, P < 0.001), lower TLC (76 +/- 15 vs 85 +/- 13%pred, P = 0.02) and lower PImax (68 +/- 20 vs 87 +/- 22 cmH2O, P = 0.003), but comparable DLCO (84 +/- 15 vs 88 +/- 20%pred, P = N.S.), and PEmax (99 +/- 25 vs 96 +/- 22 cmH2O, P = N.S.). In conclusion, our data suggest that respiratory abnormalities, such as restrictive defects, airway obstruction, and inspiratory muscle weakness, are more pronounced in patients with severe CHF than in those with mild-to-moderate disease. Further studies are required to investigate the extent to which these abnormalities contribute to dyspnoea during daily activities in patients with heart failure.

Respiratory complications after coronary artery bypass surgery with unilateral or bilateral internal mammary artery grafting

BACKGROUND AND STUDY OBJECTIVE

Use of bilateral internal mammary artery (IMA) grafts during coronary artery revascularization procedures carries the potential for increased incidence of postoperative respiratory complications compared with use of unilateral IMA grafts. The purpose of this study was to compare the incidence of respiratory complications such as hypoxemia, atelectasis, pleural effusion, and diaphragmatic dysfunction in patients who received one or both IMAs as conduit grafts.

DESIGN

Prospective, comparative study.

SETTING

Surgical ICU at a tertiary teaching hospital.

PATIENTS

Seventy-five patients with bilateral and 75 patients with unilateral IMA grafts.

MEASUREMENTS

Serial postoperative PaO2/fraction of inspired oxygen measurements, radiographic scores of atelectasis and pleural effusion, duration of mechanical ventilation, length of ICU and hospital stay, and incidence of pneumothorax, pneumonia, and wound infection.

RESULTS

There was a higher incidence (51% vs 25%; p=0.002) and severity (0.48+/-0.09 vs 0.15+/-0.05 on the first postoperative day, 0.39+/-0.07 vs 0.27+/-0.07 on the fourth postoperative day, mean+/-SEM; p=0.004) of postoperative right lower lobe atelectasis in the group who received bilateral IMA grafts than in those who received left IMA grafts. This finding probably reflects the effects of additional surgical intervention on the right side of the chest. Incidence and severity of pleural effusion, gas exchange impairment, duration of mechanical ventilation, ICU and hospital stay, and incidence of pneumothorax, pneumonia, and wound infection were not influenced by use of bilateral IMA grafts (p>0.05).

CONCLUSION

We conclude that use of bilateral IMA grafts during coronary artery revascularization does not increase the incidence of postoperative respiratory complications compared with unilateral IMA grafting.

Phrenic nerve dysfunction after cardiac operations: electrophysiologic evaluation of risk factors

BACKGROUND AND STUDY OBJECTIVE

Phrenic nerve injury may occur after cardiac surgery; however, its cause has not been extensively investigated with electrophysiology. The purpose of this study was to determine by electrophysiologic means the importance of various possible risk factors in the development of phrenic nerve dysfunction after cardiac surgical operations.

DESIGN

A prospective study was conducted.

SETTING

A tertiary teaching hospital provided the background for the study.

PATIENTS

Sixty-three cardiac surgery patients on whom surgical operations were performed by the same surgical team constituted the study group. Mean (+/-SD) age and ejection fraction were 63+/-5 years and 50+/-10%, respectively.

INTERVENTIONS

Measurement of phrenic nerve conduction latency time after transcutaneous stimulation preoperatively and at 24 h and 7 and 30 days postoperatively.

RESULTS

Thirteen patients had abnormal phrenic nerve function postsurgery, 12 on the left side and one bilaterally. Logistic regression analysis revealed that among the potential risk factors investigated, use of ice slush for myocardial preservation was the only independent risk factor related to phrenic nerve dysfunction (p=0.01), carrying an 8-fold higher incidence for this complication. In contrast, age, ejection fraction of the left ventricle, operative/bypass/aortic cross-clamp time, left internal mammary artery use, and diabetes mellitus were not found to be associated with phrenic neuropathy. The postoperative outcome of patients who received ice slush compared with that of those who had cold saline solution did not differ in terms of early morbidity and mortality.

CONCLUSION

Among the risk factors investigated, only the use of ice slush was significantly associated with postoperative phrenic nerve dysfunction. Therefore, ice should be avoided in cardiac surgery, since it does not seem to provide additional myocardial protection.

Low-dose amiodarone-related complications after cardiac operations

OBJECTIVE

High-dose preoperative amiodarone therapy has been implicated as a risk factor for serious complications after cardiac operations. To investigate the effect of preoperative low-dose amiodarone treatment on early postoperative outcome after cardiac operations, we prospectively studied 88 patients.

METHODS

Forty-four patients were receiving amiodarone (mean daily dose +/- standard deviation, 205 +/- 70 mg/day) and 44 patients were controls matched in pairs. The following parameters were recorded after the operation in all patients: (1) the ratio of oxygen tension to inspired oxygen fraction on arrival in the intensive care unit and 2, 4, 6, 10, 14, 18, and 22 hours thereafter; (2) the occurrence of acute respiratory distress syndrome; (3) early postoperative cardiac complications; and (4) the type and number of inotropic agents or vasopressors (or both) needed.

RESULTS

No difference in the ratio of oxygen tension to inspired oxygen fraction was noted at the various time intervals between amiodarone-treated patients and control patients. Overall, only one patient had acute respiratory distress syndrome in the amiodarone group, but he had multiple other factors known to predispose to acute lung injury. Several cardiac complications, such as pulmonary edema, temporary pacing, and need for intraaortic balloon pump counterpulsation, were observed more frequently in amiodarone-treated patients than in control patients. In addition, amiodarone-treated patients required more frequent inotropic support (73% vs 43%, p = 0.003) and more inotropic drugs or vasopressors (or both) per patient than did control patients (1.4 +/- 1.1 vs 0.6 +/- 0.8, p = 0.002).

CONCLUSION

Preoperative low-dose amiodarone therapy does not seem to be related to significant postoperative lung toxicity, but it is associated with various cardiac complications and an increased need for more intense inotropic support after cardiac operations. These findings may be related to the drug's depressant effect on the myocardium.

Clinical evaluation of four tumor markers in malignant and benign pleural effusions

Total sialic acid (TSA), lipid-bound sialic acid (LSA), ferritin and carcinoembryonic antigen (CEA) were evaluated in 55 patients with malignant pleural effusions and in 32 patients with benign (exudative) pleural effusions. No significant differences were found in the pleural fluid TSA, LSA and ferritin levels between malignant and benign conditions. CEA levels in malignant effusions were significantly higher than those in benign effusions (43.13 +/- 72.8 ng/ml versus 2.6 +/- 5.56 ng/ml, p less than 0.01). At a cut-off level of 5 ng/ml, 60% of the patients with cancer showed elevated pleural fluid CEA levels. The specificity and diagnostic accuracy of CEA in distinguishing malignant from benign pleural exudates were both very high (91% and 71% respectively). Therefore, of the four markers investigated, only CEA could be a valuable tool in the detection of pleural malignancy.